1. Field of the Invention
The present invention relates to an automotive dynamoelectric machine that is used in a vehicle, and particularly relates to a three-phase output terminal portion for extracting three-phase alternating current output from an automotive dynamoelectric machine.
2. Description of the Related Art
In recent years, dynamoelectric machines are increasingly being used as generator motors by extracting and using three-phase alternating current output from dynamoelectric machines directly, or using alternating-current direct-current (ac/dc) converters.
In conventional automotive alternators, a plurality of terminals for extracting three-phase alternating-current output are molded integrally into a fan guide so as to be embedded in a resin, and a connector portion for external connection is also molded integrally in the resin (see Patent Literature 1, for example).
Patent Literature 1: Japanese Patent Laid-Open No. HEI 05-268753 (Gazette)
In the field of dynamoelectric machines of this kind, technical innovations are leading to increases in electric loads on vehicles, and electric currents flowing through dynamoelectric machines are also increasing. Thus, thick wires are used for three-phase wires connecting the dynamoelectric machines with external equipment so as to be able to cope with large currents.
In conventional automotive alternators, the three-phase alternating-current output is extracted by mounting the external three-phase wires into the connector portion. Here, the three-phase wires and the terminals are connected by the connector, and since the connection is made by spring force, connection resistance at the contacts is increased, and the connecting force is small.
Thus, if large currents flow, the quantity of heat generated at the contacts between the three-phase wires and the terminals is large. The temperature of the terminals thereby increases excessively, and in the worst cases problems may arise such as contact portions welding together, the resin melting, etc. Since the quantity of heat generated is greater in the case of alternating current than with direct current, it is necessary for the connection resistance at the contacts to be reduced if three-phase alternating-current output is to be extracted.
If thick three-phase wires are used, vibration of the vehicle shakes the three-phase wires, and excessive stresses act on connection portions between the three-phase wires and the terminals. Thus, there has been a risk that problems may arise such as the connection portions between the three-phase wires and the terminals being abraded, or damaged, etc.